:root{--primary-color:#4a90e2;--primary-hover:#357abd;--secondary-color:#6c757d;--secondary-hover:#5a6268;--success-color:#28a745;--danger-color:#dc3545;--warning-color:#ffc107;--info-color:#17a2b8;--light-color:#f8f9fa;--dark-color:#343a40;--white-color:#ffffff;--black-color:#000000;--gray-color:#6c757d;--gray-dark-color:#343a40;--gray-light-color:#f8f9fa;--body-bg:#ffffff;--body-color:#212529;--link-color:#007bff;--link-hover-color:#0056b3}*{box-sizing:border-box;margin:0;padding:0}body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;line-height:1.5;color:var(--body-color);background-color:var(--body-bg);padding:20px}.container{max-width:1200px;margin:0 auto;padding:20px}h1{text-align:center;margin-bottom:30px;color:var(--dark-color)}.upload-section{text-align:center;margin-bottom:30px}.file-input{display:none}.file-label{display:inline-block;padding:12px 24px;background-color:var(--primary-color);color:var(--white-color);border-radius:4px;cursor:pointer;transition:background-color .3s}.file-label:hover{background-color:var(--primary-hover)}.controls{max-width:600px;margin:0 auto 30px;padding:20px;background-color:var(--light-color);border-radius:4px;box-shadow:0 2px 4px rgba(0,0,0,.1)}.control-group{margin-bottom:15px}.control-group label{display:block;margin-bottom:5px;font-weight:500}.control-group input{width:100%;padding:8px;border:1px solid #ddd;border-radius:4px}.video-preview{max-width:800px;margin:0 auto 30px;background-color:var(--light-color);border-radius:4px;overflow:hidden}video{width:100%;display:block}.actions{text-align:center;margin-bottom:30px}.primary-button,.secondary-button{padding:12px 24px;border:none;border-radius:4px;cursor:pointer;font-weight:500;margin:0 10px;transition:background-color .3s}.primary-button{background-color:var(--primary-color);color:var(--white-color)}.primary-button:hover{background-color:var(--primary-hover)}.secondary-button{background-color:var(--secondary-color);color:var(--white-color)}.secondary-button:hover{background-color:var(--secondary-hover)}.primary-button:disabled,.secondary-button:disabled{opacity:.6;cursor:not-allowed}.preview-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(150px,1fr));gap:15px;margin-bottom:30px}.preview-image{width:100%;height:auto;border-radius:4px;box-shadow:0 2px 4px rgba(0,0,0,.1)}.progress-bar{width:100%;height:20px;background-color:var(--light-color);border-radius:10px;overflow:hidden;margin-bottom:30px;display:none}.progress-fill{width:0;height:100%;background-color:var(--primary-color);transition:width .3s ease-in-out}@media (max-width: 768px){.container{padding:10px}.controls{padding:15px}.primary-button,.secondary-button{width:100%;margin:10px 0}.preview-grid{grid-template-columns:repeat(auto-fill,minmax(120px,1fr))}}